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eInvoicing Documentation


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eInvoicing in Belgium


Federal Public Service Policy and support (BOSA)

NB: BOSA works in close cooperation with other public entities at federal and regional levels as well as the private sector.


The transposition of Directive 2014/55/EU is complete (loi du 7 avril 2019);

Additionally, suppliers of Flemish government are obliged to send eInvoices since 1 January 2018. 

Transposed the Directive 2014/55/EU


Use of the extra year for compliance of non-central entities (by )


Mandatory for

Submitting: Economic operators;
Receiving and processing: Central, regional and local contracting authorities and entities.


(*European Standard on eInvoicing mandatory for contracting authorities since  )



The Belgian approach is platform-agnostic.

More specifically, it relies on the Peppol interoperability model that specifies the proper, consensus-based set of rules that allow cooperation across multiple platforms.

The Belgian public sector supports this approach by, among others, operating Mercurius, a Peppol-alignead "e-mailroom", that can be used by any Belgian contracting authority to receive their eInvoices.

It is made instrumental via a web portal, which provides all economic operators and contracting authorities with an integrated access to their B2G eInvoicing flow. This portal creates transparency and lowers the support costs.

The choice of Peppol considerably facilitates the alignment of the Belgian public sector with the Directive 2014/55.

Use of an ad hoc CIUS and/or Extensions



The federal law modifying the VAT code of 17.12.2012 puts eInvoicing on an equal footing with paper invoicing, legalising the use of eInvoices as of 1 January 2013. This law links the use of eInvoices with the willingness of the receivers to process it. This law does not mandate the use of eInvoices in B2G procurement.

The regional government of Flanders decided in 2016 to make the use of eInvoices in B2G procurement mandatory as of 1 January 2017 for all its regional entities.

The federal government decided to mandate the use of B2G eInvoicing since 1 January 2018 for all federal entities, for contracts above EUR 135k.

The main entity of the Government of the Brussels Region now accepts eInvoices, but has not made them mandatory yet. 

The other regional governments in Belgium will follow and soon enable the receiving and processing of eInvoices.

The transposition of the Directive 2014/55/EU is completed (loi du 7 avril 2019).

eInvoicing solutions

In Belgium, eInvoices to the public sector can easily be submitted by any supplier who is able to send Peppol invoices. 

Technically, these invoices are concentrated into one single e-mailroom, the Mercurius platform, where each public sector entity picks up his incoming eInvoices at his own pace.  The federal government is charged with the setup, operations and maintenance of Mercurius. This platform has a web interface that allows any sender to check the status of their invoices. This web interface is also accessible by intermediates/service providers and customer representatives, so that all parties share the same “track and trace” information.

The Mercurius Platform is a B2G eInvoicing solution based on the ePRIOR platform, which was developed and used by the European Commission. At the end of its pilot phase, Belgium decided to integrate Mercurius with the Peppol interoperability framework, official as of 1 April 2016, going one step further towards interoperability with the private sector. 

Approach for receiving and processing

Mercurius centralises the reception of eInvoices to the public sector, so economic operators are sure to be able to send all their eInvoices to any public institution using the same method. The processing of eInvoices, however, is not harmonised. Each public contracting authority is free to apply the processing that best fits its own context. On the other hand, contracting authorities recognise the value of streamlining their processing practices. A best practices exchange and reflection group has been established for this purpose.

Economic operators can submit an electronic invoice in two ways:

  1. By applying the Peppol interoperability framework;
  2. For the ones not yet able to apply the Peppol framework: by using the manual invoice submission form available on the web-portal of the Mercurius platform (only for Belgian operators).

As the Peppol interoperabilty framework gains more and more traction within the IT sector, soon more and more affordable eInvoicing solutions will arise. More information on the roll out of the Peppol framework in Belgium, including a list of active Peppol Access Point service providers, is available on the official page of the Belgian Peppol Authority.

eInvoicing implementation in sub-central level contracting authorities 

The eInvoicing model in place is a Peppol-based strategy, which is used by 1 400 contracting authorities. Mercurius acts as eInvoicing policy enforcement mechanism to align the public sector with the Peppol approach and ensure the exchanges of eInvoicing (consequently, also the private sector).  

The European standard is partially implemented due to the lack of awareness and mobilisation and the excessive dominance of the single-platform-model. 

UBL.BE is a private implementation and is the extension in place in Belgium. it extends EN to offer other ways to support eInvoicing scenarios. 

The expected benefits of eInvoicing implementation are the cost and operational savings and the reduction of administrative burden. 

Status on the implementation of the European Standard on eInvoicing (EN)

The Belgian government expects that the infrastructure developed between 2015 and 2017 will greatly facilitate the adoption of the EN. They intend to take advantage of the Peppol interoperability framework to implement the eInvoicing Directive, in order to offer practical solutions to economic operators, and to promote their reuse for B2B eIvoicing. The EN will take over the role of common denominator format. Cross-sector eInvoicing will be much easier thanks to this key asset. Indeed, generalization of B2G eInvoicing and cross-sector eInvoicing face similar challenges, so the uptake of B2G eInvoicing should positively affect cross-sector eInvoicing. The design of the EN is aligned with this approach.

Mercurius will also facilitate the implementation of the Directive, offering tools and support to the private and the public sectors to cooperate more effectively.

As of 20 November 2019, 1 400 contracting authorities are using the services of Mercurius to help them fulfill their obligations derived from the Directive. As the onboarding of contracting authorities progresses, so does the size of the market of cross-sector inbound eInvoices processing solutions. This in turn stimulates the IT sector to ship suitable solutions at affordable prices.  Up to now, this onboarding level is the result of disparate and voluntary efforts.

In complement, the federal government is developing a system, called Hermes, that converts EN-compliant (Peppol BIS) eInvoices into human-readable equivalents (PDF) and transmits them by email. This systems offers a much larger reach to senders of such eInvoices. It is expected that Hermes will significantly contribute to stimulating the senders, thereby helping the government entities to pay back the investments that they must make to meet the obligations of the Directive.  In turn, this will also have a positive influence on the adoption of eInvoicing by contracting authorities, and on the development and release of suitable and affordable eInvoice processing solutions (inbound and outbound) .

Our National website has just been revamped, to (a) provide up to date key information to the various target-groups (enterprises, government, citizens, IT-sector, accountants) and (b) improve circulation of information on the market, thanks to a partnership system. This partnership system is also used in synergy with Hermes, to provide invoice receivers with a list of eInvoice processing solutions, thereby helping them to find the solution that best suits their specific needs and expectations.

Additional initiatives complement the communication strategy, such as the organisation of the Belgian eInvoicing summit.

Monitoring eInvoicing implementation 

There is a monitoring system in place at both central and sub-central levels. Mercurius ensures partially the monitoring, as this is not an obligation to use this platform. 

The measurement units for this monitoring are the number of suppliers using eInvoicing, the number of invoices that are submitted electronically and the number of eInvoices submitted in a specific syntax. For all the eInvoices, the syntax used is OASIS UBL 2.1. 

Please see here, the latest statistic and results for the eInvoicing implementation:

Use of Core Invoicing Usage Specifications (CIUS) at national level

Belgium uses the Peppol CIUS. There is no ad hoc CIUS version. To date, no need for such an additional specification has been identified.

Additional information

Experience gained with the inbound eInvoicing scenario has led many of the customers to extend their ambitions to other inbound and outbound flows, such as eOrdering, outbound invoicing, among others. This creates new opportunities to exploit the infrastructure that has been put in place in the past. An eOrdering pilot phase is in execution. The Flemish Government has the lead on this pilot. A new pilot, focusing on outbound invoicing, is also in preparation, in collaboration with the Government of the Brussels Region.

Are you aware of further developments on eInvoicing B2G in this country? Contact us via the link Something wrong with this page? at the bottom of this page.
You can also access the 2016, 2017, 2018 and 2019 eInvoicing Country Sheets via the eInvoicing User Community.


Last updated:  Jun 12, 2020 18:29